Currently, hundreds of temperature sensors are attached to satellites during ground testing. The temperature sensors require power lines for receiving electrical energy and communication lines for transmitting temperature readings to, for example, a central processor. However, the weight of the power and communication lines and associated components significantly contributes to the overall weight of the satellite. Therefore, the temperature sensors typically are removed prior to launch to reduce the overall weight of the satellite and, as a result, reduce the costs associated with launching the satellite.
The removal of temperature sensors described above is a delicate and tedious process that typically requires hundreds of man-hours to complete. Therefore, it would be desirable to avoid the time, difficulty and expense associated with removing temperature sensors from satellites prior to launch.
One solution is to use temperature sensors that are powered wirelessly and communicate with a receiver wirelessly, thereby eliminating the excess weight associated with power and communication lines.
Known wireless temperature sensor systems typically include a radio frequency (“RF”) transmitter that uses a standard transmission protocol such as ZIGBEE®, BLUETOOTH® or active radio frequency identification (“RFID”). However, in certain applications, such as defense satellites, there is a concern about RF leakage and, in particular, the potential detection of RF leakage by an adversary. Therefore, it would be desirable to avoid creating a detectable RF signature. Indeed, certain users have outright bans on the use of RF communication.
Accordingly, there is a need for a sensor network that is powered wirelessly, communicates wirelessly, and does not produce a detectable RF signature.